JP2001252888A - Grasping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grasping device capable of grasping an object having an arc- shaped or polygonal grasping surface while preventing fall of it for preventing it from being broken. SOLUTION: On an arm installation part 22 of a main body part 20, a first base part arm 31 and a second base part arm 32 are installed to be oscillated by an arm actuation mechanism 80. First grasping arms 35 with first grasping parts 40 are each installed on the first base part arm 31 and the second base part arm 32, second grasping arms 36 with second grasping parts 41 are each installed on the first grasping arm 35 to freely oscillate, and third grasping arms 38 with third grasping parts 42 are each installed on the second grasping arm 36 to be capable of oscillation. First energization mechanisms 43 are each installed along the second grasping arm 36 and arm installation part 22 for oscillation energization in a grasping direction for holding, and second energization means 44 are each installed along the first grasping arms 35 and third grasping arms 38 for oscillation energization in the grasping direction for holding. By grasping action, therefore, the third grasping parts 42 and the second grasping parts 41 get in contact with a grasping surface in order, and then the first grasping parts 40 get in contact, so an object can be grasped as if it is held in both arms, thereby it can be grasped while fall is prevented to prevent it from being broken.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gripping device for gripping explosives and the like.

[0002]

2. Description of the Related Art A boom is attached to an airframe so that it can swing up and down.
An explosives handling machine has been proposed in which an arm is attached to the boom so as to swing up and down, and a gripping device is attached to the arm. 13 and 14 have been proposed as the aforementioned gripping device. The main body 1 has a first arm 2 and a second arm 3 with an axis 4
It is mounted so that it can swing freely. A gripping piece 5 is attached to the tip of the first arm 2 and the second arm 3. A cylinder 7 is mounted on a bracket 6 fixed to the main body 1. A pair of links 9 is pivotally attached to a movable plate 8 which is moved by the cylinder 7, and a lever 10 pivotally attached to each link 9 is connected to the shaft 4.
It is stuck to. When the movable plate 8 is moved upward by the cylinder 7, the first arm 2 and the second arm 3 swing in the separating direction, and the pair of gripping pieces 5 grip the object to be gripped.

[0003]

The above-mentioned gripping device performs a gripping operation by pressing the pair of gripping pieces 5 against an object to be gripped by the thrust of the cylinder 7, so that the thrust of the cylinder 7 is increased and the pair of gripping pieces 5 are moved. The object to be gripped is prevented from dropping by pressing against the object to be gripped with a strong force.

[0004] For this reason, a strong force acts on the object to be grasped, and there is a risk of explosion if the object to be grasped is an explosive.
Objects to be grasped are soft or easily deformed (such as cardboard boxes)
In the case of, there is a risk of breakage such as crushing or deformation.

When the object to be grasped is an arc-shaped outer periphery such as a flowerpot, a pair of grasping pieces 5 are used to form an arc-shaped outer peripheral surface of the object.
Since the point is gripped, there is a possibility that falling cannot be prevented even if the gripping piece 5 is pressed with a strong force.

Accordingly, an object of the present invention is to provide a gripping device which can solve the above-mentioned problems.

[0007]

A first aspect of the present invention provides an arm mechanism having a main body 20, and one side arm and the other side arm which are attached to the main body 20 so as to be swingably opposed to each other. 30 and
An arm operating mechanism 80 that swings the one arm and the other arm in a gripping direction and a grip releasing direction is provided. The one arm and the other arm follow the shape of the grip surface of the object to be gripped, and It is a holding device characterized by having a plurality of holding portions in contact with a plurality of positions on a surface.

According to the first aspect of the present invention, the object to be grasped is vertically held by the plurality of grasping portions of one arm and the plurality of grasping portions of the other arm. The object to be gripped can be gripped so as not to fall even if it is pressed with a weak force. Therefore, the object to be gripped can be prevented from falling,
Damage to the object to be grasped can be prevented. For example, when the object to be grasped is an explosive, the explosive can be held so as not to explode and prevented from falling. When the object to be grasped is soft or easily deformed, it can be grasped so as not to be crushed or deformed, and fall can be prevented. In addition, the object to be gripped having a gripping surface having an arc shape or a polygonal shape can be reliably held so as not to fall.

According to a second aspect of the present invention, there is provided an arm mechanism 30 having a main body 20, an arm and a plurality of other arms attached to the main body 20 so as to swing freely and opposingly. An arm operating mechanism 80 that swings each other arm in a gripping direction and a grip release direction is provided. The one arm and each other arm follow the shape of the gripping surface of the object to be gripped, and It is a holding device characterized by having a plurality of holding portions in contact with a position.

According to the second aspect of the present invention, the object to be grasped is moved up and down by a plurality of grips on one arm and a plurality of grips on a plurality of other arms.
Since the object is gripped so as to be held in the circumferential and lateral directions, the object to be gripped can be held so as not to fall even if the gripping portion is pressed against the object to be gripped with a small force.

That is, the gripper has the effect of the first invention and further has a plurality of other arms, so that the gripper is gripped by contacting at least three points of the gripped object. That is, since the circumferential or horizontal direction is also gripped by being added in the vertical direction, the gripping ability is improved, it is easy to grip, and a long gripped object can be stably gripped laterally, and a spherical gripped object can be gripped. Can be gripped securely so as not to fall.

[0012] In a third aspect based on the first or second aspect, the plurality of gripping portions include a fixed gripping portion that swings with one side arm and the other side arm, and one side arm and another side arm. This is a gripping device having a movable gripping portion that swings together with the external force and swings in a grip release direction.

According to the third aspect of the present invention, the movable gripper comes into contact with the gripping surface of the object to be gripped by swinging the one arm and the other arm in the gripping direction. By swinging in the holding release direction so that the fixed holding portion is in contact with the holding surface, the object to be held can be reliably held by holding the object to be held between the fixed holding portion and the movable holding portion.

In a fourth aspect based on the first or second aspect, the plurality of gripping portions include a fixed gripping portion that swings with one side arm and the other side arm, a one side arm and another side arm. A gripping device having a plurality of movable gripping portions that swings together with each other and swings in a grip release direction by an external force.

According to the fourth aspect of the present invention, since the plurality of movable gripping portions sequentially come into contact with the gripping surface of the gripped object and sequentially swing in the grip release direction, the at least three gripping portions can be used to move both sides of the gripped object. Can be held by holding each. Therefore, the object to be grasped can be firmly grasped so as not to fall.

According to a fifth aspect of the present invention, in the third or fourth aspect, the movable gripping portion is held at a position oscillated in the gripping direction by an urging mechanism, and is moved in the grip releasing direction by an external force greater than the urging force. This is a gripping device that swings.

According to the fifth aspect, the pressing force of the movable gripping portion against the object to be gripped is a force corresponding to the urging force of the urging means, and the pressing force is applied to one arm and the other arm. It can be made smaller than the oscillating force, and it is possible to reliably prevent damage to the object to be gripped.

In a sixth aspect based on the fifth aspect, the one side arm and the other side arm are a first arm swinging with respect to the main body 20, and a second arm swinging with respect to this arm. Arm and a third arm that swings with respect to the second arm, and a fixed gripper is attached to the first arm, and a movable gripper is attached to the second arm and the third arm. A first urging mechanism 43 that oscillates and holds the second arm in the gripping direction is attached between the main body 20 and the second arm, and swings the third arm in the gripping direction. This is a gripping device in which a second urging mechanism 44 for urging and holding is attached across the first arm and the third arm.

According to the sixth aspect, the second arm swings with respect to the first arm, so that the first movable gripping portion swings with respect to the fixed gripping portion. As the third arm swings with respect to the arm, the second movable gripper swings with respect to the first movable gripper, so that each gripper has a shape of a gripping surface of an object to be gripped. Since the swinging surface follows and smoothly swings, the gripping surface can be securely gripped so as to firmly hold an object to be gripped having an arc shape or a polygon shape.

Further, since the urging force of the first urging mechanism 43 directly acts on the second arm and the urging force of the second urging mechanism 44 directly acts on the third arm, a small force is applied. Using the first and second urging mechanisms 43 and 44, the second and third arms can be oscillated and held by a predetermined urging force. Therefore, the width of the one side arm and the other side arm does not become large by the first and second urging mechanisms 43 and 44, and it becomes possible to enter a narrow place and to be held in a narrow place.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG.
And an arm mechanism 30 swingably attached to the main body 20.
And the arm operating mechanism 80 that swings the arm mechanism 30 constitute a gripping device. The main body 20 is a construction machine mounting section 2.
1 and an arm mounting portion 22 provided thereunder. The construction machine mounting portion 21 has a pair of vertical plates 23, and is mounted to the tip of the arm of the construction machine with a pin. The arm mounting part 2
2 is a substantially downward U-shaped horizontal plate 24 and a pair of vertical plates 25,
A cover plate 26 is fixedly attached to the upper portion of the pair of vertical plates 25.

The arm mechanism 30 has a first base arm 31 and a second base arm 32. First base arm 31 and second base arm 3
Reference numeral 2 denotes a substantially T-shaped arm mounting portion 31a, 32a and a connecting portion 31b, 32b, and a longitudinally intermediate portion of each arm mounting portion 31a, 32a is swingably supported by a pin 33 with respect to the arm mounting portion 22, The first base arm 31 and the second base arm 32 swing in the approaching direction and the separating direction. Each of the connecting portions 31b and 32b is a pin 3
4 is connected rotatably.

A first gripping arm 35 is mounted on one longitudinal end of the arm mounting portion 31a of the first base arm 31. A second gripping arm 36 is attached to the first gripping arm 35 by a first pin 37 so as to be swingable in the gripping direction. A third gripping arm 38 is attached to the second gripping arm 36 so as to be swingable with a second pin 39. The first, second, and third gripping arms 35, 3
6, 38 include first, second, and third gripping portions 40, 41, 42.
Is installed. The first, second, and third grippers 40, 4
Numerals 1 and 42 are made of an elastic material such as rubber or soft resin, and have a plate-like shape having irregularities, and have a cushioning function when pressed against an object to be grasped.

A first urging means 43 is mounted on the second gripping arm 36 and on the fixed side, for example, the vertical plate 25 of the arm mounting portion 22, and the second gripping arm 36 is in the position shown in FIG. It is urged and held, and swings in the grip release direction when an external force acts. A second biasing means 44 is attached to the third gripping arm 38 and the first gripping arm 35, and the third gripping arm 38 is provided.
Is biased and held at the position shown in FIG. 1 and swings in the grip release direction when an external force acts.

The first, second, and third gripping portions 40, 41,
Reference numeral 42 denotes a first gripping portion 40 which is disposed substantially linearly at intervals in the longitudinal direction when the gripping object is in a free state in which it is not gripped.
Is the uppermost position and is closest to the gripping direction.
Is the middle position in the gripping direction at the middle in the vertical direction, and the third gripping portion 42 is the lowermost position closer to the outside in the gripping direction. The first gripper 40 swings together with the first base arm 31 and the first base arm 31
It is a fixed gripping part that is fixed without swinging with respect to. The second and third gripping portions 41 and 42 swing in the gripping direction together with the first base arm 31, and when an external force is applied, swing to release the first base arm 31 and are movable gripping portions. .

As described above, the first base arm 31, the first, second, and third gripping arms 35, 36, 38 and the first, second, and third gripping portions 40, 41, 42 It can be swung in the holding and releasing directions with respect to the arm mounting portion 22 (main body portion 20),
One side arm is provided with a plurality of gripping portions that grip so as to be held by swinging while following a gripping surface of an object to be gripped.

The first, second and third gripping arms 3 are attached to one longitudinal end of the arm mounting portion 32a of the second base arm 32.
5, 36, 38 are mounted in parallel at a distance in a direction perpendicular to the swinging direction. These first, second and third
The first, second, and third gripping portions 4 are provided on the gripping arms 35, 36, and 38.
0, 41, and 42 are attached in the same manner as described above. This second
The first, second, and third gripping arms 35, 36, 38 attached to the base arm 32 are attached to the first base arm 31 on both sides in a direction (hereinafter, referred to as a width direction) orthogonal to the swing direction. The first, second, and third gripping arms 35, 36, 38 are located. That is, a pair of first, second, and third grips attached to the second proximal arm 32 on both sides of the first, second, and third gripping arms 35, 36, and 38 attached to the first proximal arm 31. Arms 35, 36,
38 are located.

That is, the second base arm 32 and the first
Second and third gripping arms, 35, 36, 38 and a pair of first and
The second and third gripping portions 40, 41, and 42 are used to attach the arm mounting portion 22.
It forms a pair of other arms provided with a plurality of gripping portions which are swingable with respect to the (main body portion 20) in the gripping and releasing directions and follow the gripping surface of the object to be gripped and swing. The pair of other arms are located on both sides in the width direction of the one arm.

The specific shape of the arm mechanism 30 will be described with reference to FIGS. The first base arm 31 and the second base arm 32 form a pair of substantially T-shaped plates 45 by a spacer 4.
6 and fixed at intervals. The first gripping arm 35 is inserted between the pair of plates 45 and the bolt 4
7 is detachably attached. As shown in FIG. 3, the first gripping arm 35 attached to the first base arm 31 is flat and has a first pin hole 48 and a second pin hole 49. The second gripping arm 36 has a pair of plates 50, and the first gripping arm 35 is inserted between the pair of plates 50, and the pin 37 is inserted into the first pin hole 48 so as to be swingably connected. . The third gripping arm 38 has a pair of plates 51, which are inserted between the pair of plates 50 of the second gripping arm 36 and are swingably connected by pins 39.

The first gripping arm 3 attached to the second base arm 32
5 is a vertical plate 52 and a horizontal plate 5 as shown in FIGS.
3, a pair of mounting portions 54 fixed to both ends of the horizontal plate 53, and a pair of first grip portions 40 fixed to the mounting portions 54 with bolts. The first pin hole 48 and the second pin hole 49 are formed in each of the mounting portions 54. As shown in FIG. 4, the vertical plate 52 is inserted between the pair of plates 45 of the second base arm 32 and fixed with bolts 47, and the pair of mounting portions 54 are connected to the second base arm 32.
Located on both sides of. First pin hole 48 of a pair of mounting portions 54
The second gripping arms 36 are swingably connected to each other by inserting a pin 37 into the arm. The second gripping arms 38 are pivotally connected to the pair of second gripping arms 36 by pins 39, respectively.

Thus, by removing the vertical plate 52 from the second base arm 32, the pair of first, second and third gripping arms 35, 36 and 38 can be removed. Also, by attaching the first gripping arm 35 to the second base arm 32 as shown in FIG. 3, the first, second, and third gripping arms 35 are attached to the first base arm 31 and the second base arm 32. 36 and 38 can be attached. In other words, the gripping device can be configured with two arms by making the one side arm and the other side arm the same shape.

The first urging means 43 and the second urging means 44
Has an elastic body in which a rod 61 is slidably fitted in a tubular body 60, and an elastic body, for example, a spring 62, which urges the extension stroke end. The cylindrical body 60 of the first urging means 43
Is connected to the vertical plate 25 and a link 81 described later with a pin 63, and the rod 61 is connected to the second gripping arm 36 with a pin 64. The cylindrical body 60 of the second urging means 44 is the first gripping arm 3
5 is connected by a pin 65 fitted into the second pin hole 49, and the rod 61 is connected to the third gripping arm 38 by a pin 66.

The first and second urging means 43 and 44 may use rubber or synthetic resin instead of the spring 62.
A gas such as air or nitrogen gas may be used instead of the elastic body, or a liquid and gas such as oil and nitrogen may be used.

The first and second base arms 31, 32 and the first
The gripping arm 35 is separate from the first and second base arms 31 and 32 in that a gripping arm similar to that of the related art can be attached to the first and second base arms 31 and 32. The first and second gripping devices are provided for attaching the other arm to a gripping device having two arms, or attaching one arm and a pair of other arms to a gripping device having three arms. The base arms 31, 32 and the first gripping arm 35 may be formed in an integral shape.

That is, the first swinging motion with respect to the main body 20
Arm (base arm and first gripping arm 35), a second arm (second gripping arm 36) swinging with respect to the first arm, and a swinging arm with respect to the second arm Arm (third gripping arm 3)
8) One side arm and the other side arm, a fixed arm is attached to the first arm, a first movable arm is attached to the second arm, and a second movable arm is attached to the third arm. Just attach it.

The arm operating mechanism 80 is mounted between the pair of vertical plates 25 of the arm mounting portion 22 of the main body 20. The specific structure will be described below with reference to FIGS. The middle part in the longitudinal direction of the first base arm 31 is a pair of vertical plates 2 of the arm mounting part 22.
It is swingably mounted between pins 5 by pins 33. Arm mounting part 2
A pair of links 81 are attached to the pair of vertical plates 25 by pins 82 so as to be swingable.
The two intermediate portions in the longitudinal direction are swingably connected by pins 33. A swing cylinder 83 is connected by pins 84 across the other longitudinal end of the arm mounting portion 31a of the first base arm 31 and the other longitudinal end of the arm mounting portion 32a of the second base arm 32.

When the oscillating cylinder 83 is contracted, the first and second base arms 31, 32 oscillate in the grip releasing direction as shown by the solid line in FIG. When the oscillating cylinder 83 is extended and operated, as shown by the one-dot chain line and the two-dot chain line in FIG.
The second base arms 31 and 32 sequentially swing in the gripping direction. Further, since the connecting portion 31b of the first base arm 31 and the connecting portion 32b of the second base arm 32 are connected by the pin 34, the first base arm 31 and the second base arm 32 are synchronously held in the holding direction and the holding direction. Swing in the release direction. Further, the second base arm 32 is
The first base arm 31 and the second base arm 32 are swingably connected to the link 81 which is swingably attached to the
Swings smoothly.

Next, the gripping operation of the object to be gripped will be described. FIG.
As shown in the figure, the first and second base arms 31 and 32 are swung in the grip release direction most, and the first and second opposed base arms 31 and 32 are opposed to each other.
-The third grippers 40, 41, 42 are positioned on both sides of the object to be gripped. Thereafter, the first base arm 31 and the second base arm 32 are swung in the gripping direction to grip the object to be gripped.

As shown in FIG. 10 (a), when an object to be gripped C-1 having a large diameter and a substantially circular outer surface is placed sideways to grip the outer peripheral surface, the substantially arc-shaped gripping is performed. The first grip portion 40 is in contact with the upper portion of the surface above the upper and lower central portions, the second grip portion 41 is in contact with the upper and lower central portions, and the third grip portion 42 is in contact with the lower portion. As a result, the object to be gripped C-1 is gripped by the first, second, and third gripping portions 40, 41, and 42 on both sides so that the pressing force of the gripping portion can be reduced even if the gripping surface has an arc shape. It can be made weak to prevent the object C-1 from falling. The same applies to an object to be gripped having a polygonal gripping surface.

That is, when gripping the object to be gripped C-1 as described above, the first and second base arms 31, 32 are swung in the gripping direction so that the third gripper 42 is firstly moved vertically to the center. It touches lower than part. When the first and second base arms 31 and 32 are further swung, the third holding portion 42 and the third holding arm 38 are opposed to the second urging means 44 and the first and second base arms 3 are moved.
Swings in the grip release direction relative to
The grip portion 41 contacts the upper and lower central portions.

Thereafter, when the first and second base arms 31 and 32 are further swung, the third and second grip portions 42 and 41 are moved to the third and fourth positions.
The second and first urging means 4 together with the second gripping arms 38 and 36
The first and second base arms 31 and 32 swing relative to the first and second base arms 31 and 32 in a grip release direction against the first and second base arms 31 and 32, and the first grip portion 40 comes in contact with the upper portion of the upper and lower central portions.

As shown in FIG. 10 (b), in the case of the object to be gripped C-2 having an intermediate diameter, the third grip portion 42 is shifted downward from the upper and lower central portions in the same manner as described above. Contact, second
When the grip portion 41 comes in contact with the upper portion of the upper and lower central portions, the object to be gripped C-2 is gripped and held.

As shown in FIG. 10C, in the case of the object to be gripped C-3 having a small diameter, the second gripper 41 is formed in the same manner as described above.
Is in contact with the lower part of the upper and lower central parts, and the first gripping part 40 is in contact with the upper part of the upper and lower central parts.
-3 is gripped.

When the gripping is performed as described above, the pressing force (contact pressure) of the second and third gripping portions 41 and 42 against the gripping surface of the object to be gripped is adjusted by the first and second biasing means 43 and 44. The size is commensurate with the spring force (biasing force) of the spring 62 and is substantially constant.

As shown in FIG. 11, the first, second, and
First, second and third gripping portions 4 of a pair of other arms on both sides in the longitudinal direction with the contact portions of third gripping portions 40, 41 and 42 as boundaries.
Since 0, 41, and 42 are in contact with each other, a long object to be gripped can be stably gripped so as not to be inclined in the longitudinal direction.

As shown in FIG. 12, when the objects to be gripped C-1, C-2, and C-3 are placed vertically, or when the object to be gripped is a spherical object, the first arm of one side arm is used. The second and third grips 40, 41 and 42 and the first, second and third grips 40, 41 and 42 of the pair of other arms contact three radial points with respect to the center a on the outer peripheral surface. Therefore, it can be securely held so as not to fall.

The first biasing mechanism 43 is connected to the first gripping arm 35.
And the second gripping arm 44.
May be attached across the second gripping arm 36 and the third gripping arm 38.

[Brief description of the drawings]

FIG. 1 is an overall front view of a gripping device of the present invention.

FIG. 2 is an enlarged front view of the arm mechanism.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a front view of a first gripping arm.

FIG. 6 is a side view of the first gripping arm.

FIG. 7 is a perspective view of a first gripping arm.

FIG. 8 is a front view of the arm operating mechanism.

FIG. 9 is a side view of the arm operating mechanism.

FIG. 10 is an explanatory diagram of a gripping operation.

FIG. 11 is an explanatory diagram of a state where a long object to be gripped is gripped sideways.

FIG. 12 is an explanatory view of a state in which a circular object to be gripped is held vertically.

FIG. 13 is a front view of a conventional gripping device.

FIG. 14 is a side view of a conventional gripping device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body, 2 ... 1st arm, 3 ... 2nd arm, 5 ... Grip piece, 20
... body part, 22 ... arm attachment part, 30 ... arm mechanism, 31 ... first
Base arm, 32 ... second base arm, 33 ... pin, 34 ... pin,
35: first gripping arm, 36: second gripping arm, 38: third
Gripping arm, 40: first gripping part, 41: second gripping part, 42
... Third gripping part, 43... First urging mechanism, 44... Second urging mechanism, 80... Arm operating mechanism, 81... Link, 83.

Continued on the front page F term (reference) 3C007 DS01 ES03 ES04 ES08 ET03 EU07 EU16 EV10 EV11 NS06 NS07 3F061 AA01 BA03 BA04 BA08 BB03 BC09 BD02 BE16 BE21 DB01 DB02

Claims (6)

[Claims] 1. An arm mechanism (30) having a main body (20), one side arm and another side arm attached to the main body (20) so as to swing freely and opposingly, An arm operating mechanism (80) for swinging the other arm in the gripping direction and the grip release direction, wherein the one arm and the other arm follow the shape of the gripping surface of the object to be gripped, and A gripping device having a plurality of gripping portions in contact with a position. 2. An arm mechanism (30) having a main body (20), one arm and a plurality of other arms attached to the main body (20) so as to be swingably opposed to each other; An arm operating mechanism (80) for swinging the arm and each other arm in a gripping direction and a grip release direction, wherein the one arm and each other arm follow the shape of the gripping surface of the object to be gripped, A gripping device, comprising: a plurality of gripping portions contacting a plurality of positions on a gripping surface. 3. A plurality of gripping portions, a fixed gripping portion that swings with one side arm and the other side arm, a swinging portion with one side arm and the other side arm, and a swinging direction in a grip releasing direction by an external force. The gripping device according to claim 1, further comprising a movable gripper that moves. 4. A plurality of gripping portions, a fixed gripping portion that swings with one side arm and the other side arm, a swinging portion with one side arm and the other side arm, and a swinging direction in a grip releasing direction by an external force. The gripping device according to claim 1, further comprising a plurality of movable grippers that move. 5. The movable gripping part is held at a position pivoted in a gripping direction by a biasing mechanism, and pivots in a grip releasing direction by an external force greater than the biasing force. Gripping device. 6. The one-sided arm and the other-sided arm include a main body (20).
A first arm swinging with respect to the first arm, a second arm swinging with respect to this arm, and a third arm swinging with respect to the second arm, fixed to the first arm And a first biasing mechanism (43) for swingably biasing and holding the second arm in the gripping direction, wherein the first biasing mechanism (43) is attached to the gripping portion, the second arm and the third arm, respectively. (20) A second biasing mechanism (44) attached between the second arm and the second arm for swingingly biasing and holding the third arm in the gripping direction is provided on the first arm and the third arm. The gripping device according to claim 5, wherein the gripping device is attached across.